posix_memalign(3) BSD Library Functions Manual posix_memalign(3)
posix_memalign -- aligned memory allocation
#include <stdlib.h> int posix_memalign(void **memptr, size_t alignment, size_t size);
The posix_memalign() function allocates size bytes of memory such that the allocation's base address is an exact multiple of alignment, and returns the allocation in the value pointed to by memptr. The requested alignment must be a power of 2 at least as large as sizeof(void *). Memory that is allocated via posix_memalign() can be used as an argument in subsequent calls to realloc(3), reallocf(3), and free(3). (Note how- ever, that the allocation returned by realloc(3) or reallocf(3) is not guaranteed to preserve the original alignment).
posix_memalign() should be used judiciously as the algorithm that real- izes the alignment constraint can incur significant memory overhead.
The posix_memalign() function returns the value 0 if successful; other- wise it returns an error value.
The posix_memalign() function will fail if: [EINVAL] The alignment parameter is not a power of 2 at least as large as sizeof(void *). [ENOMEM] Memory allocation error.
The posix_memalign() function conforms to IEEE Std 1003.1-2001 (``POSIX.1''). BSD April 9, 2008 BSD
Mac OS X 10.8 - Generated Wed Aug 29 19:28:19 CDT 2012